Compressed air processing system for commercial vehicle

ABSTRACT

The present disclosure provides a compressed air processing system of which the operation of supplying compressed air and the regeneration operation can be efficiently controlled by an electronic control unit. In particular, the present disclosure is characterized in that the pressure of a regeneration sequence valve installed in a regeneration line is increased over a set pressure by controlling a valve, which is electronically controlled, to switch, so the opening time of the regeneration line is delayed in comparison to the opening time of an unloader valve, whereby regeneration efficiency is improved.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation Application of InternationalApplication No. PCT/KR2020/018820 filed on Dec. 21, 2020, which claimspriority to Korean Application No. 10-2020-0178398 filed on Dec. 18,2020, the entire contents of each of the above-identified applicationsare hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates to a compressed air processing system fora commercial vehicle and, more particularly, to a compressed airprocessing system that supplies compressed air, which is used for thebraking system, suspension system, etc. of commercial vehicle, with oil,water, and foreign substance filtered out from the air, and thatregenerates an air drier by sending the compressed air backward.

BACKGROUND ART

Commercial vehicles are equipped with various operation systems that useair pressure to control the operation of the large and heavy commercialvehicles. For example, a service brake system, a pneumatic suspensionsystem, a parking brake system, etc. are such pneumatic systems.Compressed air at high pressure is required to drive such pneumaticsystems. Such compressed air is produced through a compressor, which isdriven by an engine or a driving motor, and then sent to the reservoirsof systems that use the compressed air.

The compressed air that is supplied through a compressor containsforeign substances including oil and water. Such foreign substances suchas oil and water in compressed air have a bad influence on systems suchas causing breakdown or deteriorating durability of pneumatic systems.

In order to remove oil, water, etc. contained in compressed air, a drierunit including a filter cartridge filled with a drying agent is includedin a compressed air processing system. Such a dryer unit is installed ona supply line of compressed air to discharge dry and clean air to eachsystem by not only filtering out oil, but removing water contained incompressed air flowing from a compressor.

The compressed air processing efficiency in the filter cartridgedecreases over time, and there is a need for a regeneration process thatsends compressed air processed already, backward to improve theefficiency of the filter cartridge, particularly, the water removalefficiency of the drying agent. Compressed air that has been processedalready flows back to the filter cartridge and water and foreignsubstances existing in the filter cartridge are discharged outsidethrough this regeneration process.

Various valves installed in channels are controlled when processes ofsupplying and regenerating compressed air are performed, whereby theprocess of supplying or regenerating compressed air is selectivelyperformed.

The recent trend of the automobile industry is focused on improvement offuel efficiency through light-weighting, optimal control, etc., andparticularly, commercial vehicles are gradually increasing in size dueto price competition of product transportation, so a technology forimprove energy efficiency is necessarily required. As a part,technologies of enabling an ECU to electronically control a system underoptimal conditions for air supply on the basis of vehicle informationreceived through vehicle communication are applied.

In particular, a technology of improving the driving efficiency of acompressor and preventing unnecessary consumption of compressed air byimplementing an optimal regenerating operation is required for acompressed air processing system of an electronic control type.

DISCLOSURE Technical Problem

The present disclosure has been made in an effort to solve the problemsdescribed above and an objective of the present disclosure is to providea compressed air processing system of which the operation of supplyingand regenerating compressed air can be efficiently controlled by anelectronic control unit.

In particular, another objective of the present disclosure is to solvethe problem of reduction of regeneration efficiency due to high-pressurecompressed air remaining in a compressed air supply line.

Another objective of the present disclosure is to provide a compressedair supply system that can minimize a loss of regenerating operationeven if the switching timing of a valve is changed due to aging of thevalve.

Technical Solution

In order to achieve the objectives, a compressed air processing systemfor a commercial vehicle of the present disclosure includes aregeneration sequence valve connected with a first electronic controlvalve and a second electronic control valve and configured to open aregeneration line by receiving control input through the firstelectronic control valve and the second electronic control valve, inwhich the regeneration sequence valve is configured to open theregeneration line late by a delay until reaching a preset pressure byreceiving air from the first electronic control valve and the secondelectronic control valve.

In particular, the unloader valve is configured to open in advancebefore compressed air flows into a filter cartridge through aregeneration line, whereby regeneration efficiency is improved anddurability of the unloader valve is improved.

Further, in a preferred embodiment of the present disclosure, whenregeneration is performed by switching of the electronic control valve,regenerating air is discharged not only to the unloader valve at thecompressor, but the exhaust side of the separator-cooler(sep-cooler),whereby sequence for discharging foreign substances is unified.

Advantageous Effects

According to the present disclosure, there is an effect that thepressure of a regeneration sequence valve installed in a regenerationline is increased over a switching pressure by controlling a valve,which is electronically controlled, to switch the position of the valve,so the opening time of the regeneration line is delayed in comparison tounloading of the compressor, whereby regeneration efficiency isimproved.

In particular, according to a preferred embodiment of the presentdisclosure, since the system is implemented such that the unloader valveis opened before the regeneration line is opened, there is an effectthat it is possible to prevent overpressure from being generated in thecompressed air supply line. Further, it is possible to solve the problemthat initial regeneration efficiency is decreased due to thehigh-pressure compressed air remaining in the compressed air supply linein regeneration.

Further, according to the present disclosure, since the unloader valveis opened in advance before regeneration is completely started, it ispossible to reduce shock that is applied to the unloader valve at theearly stage of regeneration, so there is an effect that the durabilityof the unloader valve can be improved.

Further, according to the present disclosure, when the regenerationsequence valve and the unloader valve are opened for regeneration andthen closed when regeneration is finished, it is possible to prevent thevalves from being rapidly closed after air is rapidly moved, by thecut-off delay function of the valves, so there is an effect that thedurability of the valve parts can be improved.

Further, according to the present disclosure, since it is possible toimplement a valve opening delay function even without adding a specificcontrol logic or other parts, in regeneration, there is an effect thatthe control logic can be simplified and the manufacturing cost can bereduced.

Further, according to a preferred embodiment of the present disclosure,there is an effect that it is possible to minimize a loss of compressedair during regenerating operation through a delay of the regenerationsequence valve even if the switching timing of a valve is changed due toaging of the valve.

Further, according to a preferred embodiment of the present disclosure,since it is possible to discharge compressed air not only to theunloader valve at the compressor, but to the exhaust side of theseparator-cooler(sep-cooler), there is an effect that it is possible toeffectively discharge foreign substances remaining in the sep-cooler inregeneration process.

Further, according to a preferred embodiment of the present disclosure,since a large amount of compressed air can be discharged to thesep-cooler with the unloader valve closed, there is an advantage that itis possible to effectively discharge oil adhering to the inside of thesep-cooler.

DESCRIPTION OF DRAWINGS

FIG. 1 shows a compressed air processing apparatus according to a firstembodiment of the present disclosure.

FIG. 2 shows a compressed air processing apparatus according to a secondembodiment of the present disclosure.

BEST MODE

In order to achieve the objectives, a preferred embodiment of thepresent disclosure provides a compressed air processing system for acommercial vehicle that includes: a first electronic control valvecontrolled by an electronic control unit; a second electronic controlvalve controlled by the electronic control unit; and a regenerationsequence valve connected with the first electronic control valve and thesecond electronic control valve and configured to open a regenerationline by receiving control inputs through the first electronic controlvalve and the second electronic control valve, in which the regenerationsequence valve is configured to open the regeneration line late by adelay until reaching a preset pressure by receiving air through thefirst electronic control valve and the second electronic control valve.

Further, the compressed air processing system may further include: acompressor control outlet connected to the first electronic controlvalve; and an unloader valve connected to a compressed air supply lineconnected to a compressor, and pneumatically driven by receiving controlinput through the second electronic control valve, in which the firstelectronic control valve and the second electronic control valve may beconnected to a main supply line connected to the compressed air supplyline.

In this case, the first electronic control valve may be controlled toswitch the valve postion by the electronic control unit and transmitsair in the main supply line to the compressor control outlet and theregeneration sequence valve, and the second electronic control valve maybe controlled to switch the valve postion by the electronic control unitand transmits the air in the main supply line control input for theunloader valve and the regeneration sequence valve, respectively.

In particular, the electronic control unit may be configured to changethe compressor in a driving state by controlling the first electroniccontrol valve to switch and configured to open the unloader valve bycontrolling the second electronic control valve to switch; and theregeneration sequence valve may operate to open the regeneration lineonly when the first electronic control valve and the second electroniccontrol valve are both open.

Further, in regeneration, the second electronic control valve iscontrolled to open the unloader valve by the electronic control unit andthe unloader valve is opened in advance before the regeneration line isopened.

Further, the regeneration sequence valve is connected to a first controlinput line into which air flows through the first electronic controlvalve and a second control input line into which air flows through thesecond electronic control valve and that is separated from the firstcontrol input line; and is configured to be opened by air suppliedthrough the first control input line and the second control input linewhen internal pressure of the regeneration sequence valve reaches presetpressure.

Further, as another example, the regeneration sequence valve isconnected to a first control input line into which air flows through thefirst electronic control valve and a second control input line intowhich air flows through the second electronic control valve and that isconnected to the first control input line; a check valve is installedbetween an intersection of the first control input line and the secondcontrol input line and the second electronic control valve; and theregeneration sequence valve is configured to be opened by air suppliedthrough the first control input line and the second control input linewhen internal pressure of the regeneration sequence valve reaches presetpressure.

MODE FOR INVENTION

A compressed air processing system according to preferred embodiments ofthe present disclosure is described hereafter with reference to theaccompanying drawings.

Embodiments to be described hereafter are provided only for detaileddescription for those skilled in the art to be able to easily achievethe present disclosure without limiting the protective range of thepresent disclosure. Accordingly, some components may be substituted orchanged without departing from the necessary range of the presentdisclosure.

When a component is ‘connected’ with another component in the followingdescription, it includes not only direct connection of them, butconnection of them with another element or device therebetween. Further,unless explicitly described otherwise, ‘comprising’ any components willbe understood to imply the inclusion of other components rather than theexclusion of any other components.

A compressed air processing system that is described herein, similar tothe existing systems, includes a filter cartridge for removing oil,water, etc. contained in compressed air that is supplied from acompressor. The expression that compressed air is ‘processed’ hereinmeans that oil, water, and foreign substances in compressed air arefiltered out while the compressed air passes through the filtercartridge.

The compressed air processing system that is described herein isconfigured such that compressed air processed through a filter can besupplied in one direction and compressed air processed already underpredetermined conditions are sent back to be regenerated in oppositedirection.

A supply step stated herein means a process of processing air compressedby a compressor through the filter cartridge and then supplying thecompressed air to a compressed air consumption system, and aregeneration step means a process of regeneration the inside of thefilter cartridge by sending compressed air processed already back to thefilter cartridge.

FIG. 1 shows a compressed air processing apparatus according to a firstembodiment of the present disclosure. A compressed air processing system1 according to a preferred embodiment of the present disclosure includesa drier unit 10 and a valve assembly 70. The part indicated by a dashedline at the left side in FIG. 1 shows the drier unit 10 that is suppliedwith compressed air from a compressor, dries the compressed air througha filter cartridge 14, and then supplies the compressed air to the valveassembly 70. Further, the compressed air processing system 1, as shownat the other side, that is, the part indicated by a dashed dotted linein FIG. 1, may be configured to a valve assembly 70 including valvesthat supply compressed air from a downstream side of a first supply line43 to each compressed air consumption system at a divergence point 57.

As shown in FIG. 1, the compressed air processing system according to apreferred embodiment of the present disclosure is configured to be ableto process compressed air, which flows through a compressed air inletconnected to a compressor (not shown), through the filter cartridge 14and then to supply the processed air to a valve assembly 70 connected toeach compressed air consumption system.

The compressor not shown is an apparatus that suctions, compresses, andthen discharges surrounding air, and the compressed air inlet is anintake port for transmitting the compressed air discharged from thecompressor to the compressed air processing system according to thepresent disclosure. Further, as shown in FIG. 1, another compressed airinlet may be included other than the compressed air inlet 11, and asupplementary compressed air inlet 12 may be used to supply compressedair produced by another compressed air source at the outside into thesystem other than the purposes of vehicle maintenance, etc.

The compressed air supplied through the compressed air inlet 11 can besupplied to the filter cartridge 14 through a compressed air supply line41. The filter cartridge 14 is a filter structure including a dryingagent, a drying agent for securing dehumidifying performance is receivedin the cartridge, and an oil absorption filter is disposed at thecompressed air inlet to be able to remove oil.

Accordingly, the compressed air supplied through the compressed airinlet 11 is processed while passing through the filter cartridge 14. Theprocessed compressed air can be supplied to a main supply line 42 at thecenter through a main check valve 15. The main check valve 15 isprovided to prevent the processed compressed air existing in the mainsupply line 42 at the center from flowing back to the filter cartridge14.

The main supply line at the center includes a divergence point 57, and afirst supply line 43 for supplying compressed air to the valve assembly70 connected to consumption systems and a second supply line 44connected to an electronic control valve for regeneration control areconnected to the divergence point 57.

Several consumption systems are connected to the first supply line 43.For example, as shown in FIG. 1, such consumption systems may be firstand second brake systems 81 and 82, a parking brake system 84, an airsuspension system 83, a trailer supply system 85, and an assistantsupply system 86. Overflow valves 71, 72, 73, 74, and 75 for protectingcircuits may be installed in the channels connected to the systems,respectively. The overflow valves 71, 72, 73, 74, and 75 have openingpressure set to open the channels, and can apply pressure to thesystems, respectively, when the predetermined opening pressures areexceeded.

The opening pressures of the valves 71, 72, 73, 74, and 75 connected tocircuits, respectively, are set on the basis of the priorities of theconsumption circuits. Preferably, the opening pressures of the overflowvalves 71 and 72 for the service brake system are set lowest so thatcompressed air can be supplied first to the service brake. Accordingly,when compressed air is sufficiently supplied to the service brake andthe pressure in the line is increased, the overflow valves aresequentially opened in accordance with the opening pressures thereof andcompressed air can be supplied to the consumption circuit. Further,check valves for preventing backflow may be installed in the valveassembly 70.

Meanwhile, the second supply line 44 corresponds to a supply line ofcompressed air for a regeneration process. The compressed air passingthrough the second supply line 44 may be used as control input forregeneration control and may be used as compressed air for regenerationthat is supplied to the filter cartridge 14 through the regenerationline 45.

To this end, the compressed air processing system according to thepresent disclosure includes two electronic control valves and includesan electronic control unit 21 for electronically controlling theelectronic control valves. The electronic control unit 21 can beelectrically connected with another controller, sensors, or the like ina vehicle, and preferably, and is configured to be able to receivevarious items of state information of the vehicle in real time from thecontroller, sensors, of the like. For example, as in FIG. 1, theelectronic control unit 21 may be connected to pressure sensors 22, 23,and 24 for measuring pressure at specific positions in the compressedair processing system. Further, the electronic control unit 21 isconfigured to be able to control switching of the electronic controlvalves in accordance with the state information of the vehicle receivedfrom another controller, sensors such as a pressure sensor, or the like.

The electronic control valves can selectively control a supplying modeand a regeneration mode, so, in the present disclosure, it is possibleto selectively perform a supplying step or a regeneration step on thebasis of the current state of the vehicle through the electronic controlunit 21.

The two electronic control valves may be solenoid valves that areelectrically operated and they are referred to as a first electroniccontrol valve 31 and a second electronic control valve 35 herein. Thetwo electronic control valves both can be used to perform theregeneration step, and preferably, switching the positions of the twovalves may be simultaneously or sequentially controlled such that theregeneration step is finished.

In particular, according to a preferred embodiment of the presentdisclosure, the first electronic control valve 31 and the secondelectronic control valve 35 may be 3-port 2-position valves, as inFIG. 1. For example, the first electronic control valve 31 may include afirst port 32 connected to a compressor control outlet 51, a second port33 connected to the second supply line 44, and a third port 34 connectedto a vent 53. Further, the first electronic control valve 31 may have afirst position where the first port 32 and the third port 34 areconnected with each other and a second position where the first port 32and the second port 33 are connected with each other. When power is notsupplied, that is, the first electronic control valve 31 is turned off,as in FIG. 1, the first electronic control valve 31 is at the firstposition, and accordingly, the second supply line 44 is closed and thecompressor control outlet 51 is connected to the vent 53. On thecontrary, when power is supplied, that is, the first electronic controlvalve 31 is turned on, the first electronic control valve 31 is switchedto the second position, and accordingly, the second supply line 44 isconnected to the compressor control outlet through the first electroniccontrol valve 31. Accordingly, at the second position of the firstelectronic control valve 31, compressed air is transmitted to thecompressor control outlet 51, and accordingly, the compressor can bechanged into a driving state. That is, when control input is supplied tothe compressor through the compressor control outlet 51, the compressoris changed into the driving state and can assist particularly aregeneration sequence valve in the system to open.

Further, according to a preferred embodiment of the present disclosure,the first port 32 of the first electronic control valve 31 diverges atthe divergence point 56 of the line connected to the compressor controloutlet 51 such that compressed air can be supplied to the regenerationsequence valve 16 of the regeneration line 45. Accordingly, when thefirst electronic control valve 31 is controlled to be switched to thesecond position, control input can be applied to the compressor controloutlet 51 and the compressed air in the main supply line can be suppliedto a first control input line 26 of the regeneration sequence valve 16.Further, the regeneration sequence valve 16 is connected to a secondcontrol input line 27 connected with the second electronic control valve35. When the pressures of the compressed air that are applied throughthe two control input lines 26 and 27 reach a predetermined setpressure, the internal channel of the regeneration sequence valve isopened. The regeneration sequence valve will be described in more detailbelow.

Meanwhile, the electronic control valve 35 may also be a 3-port2-position valve, similar to the first electronic control valve 31.

Similar to the first electronic control valve 31 described above, thesecond port 37 may be connected to the second supply line 44 and thethird port 38 may be connected to the vent 53. Meanwhile, the first port36 of the second electronic control valve 35 is transmitted as controlinput for controlling opening/closing of an unloader valve 13.Accordingly, as in FIG. 1, the first port 36 is connected to a controlinlet of the unloader valve 13.

The unloader valve 13 is installed on an exhaust line 47 to dischargecompressed air to the atmosphere through an exhaust outlet 52. Theunloader valve 13 may be 2-port 2-position valve and may be configuredto be pneumatically driven by receiving control input through the secondelectronic control valve 35. Accordingly, compressed air that has passedthrough the second electronic control valve 35 is applied to the controlinlet of the unloader valve 13, whereby the unloader valve 13 is movedto a second position from a first position against the spring force ofthe unloader valve 13. The first position, as in FIG. 1, means the statea first port 13 a diverging from the compressed air supply line 41between the compressor and the filter cartridge 14 and a second port 13b connected to the exhaust outlet 52 are disconnected, and the secondposition means a valve position where two ports are connected to eachother and the air in the compressed air supply line 41 can be dischargedto the exhaust outlet 52.

Further, the unloader valve 13 is configured to open by receivinganother control input from the compressed air supply line 41, and isconfigured to be able to discharge air in the compressed air supply line41 to the outside when the pressure of the compressed air supply line 41exceeds a preset pressure. Accordingly, the unloader valve 13 canautomatically open even if a pressure increase that is not allowable isgenerated, whereby it is possible to prevent overpressure in thecompressed air supply line 41. In relation to this, the unloader valve13 may be configured to open in accordance with the maximum supplypressure of the compressed air supply line 41.

Meanwhile, the compressed air flowing inside through the first port 36of the second electronic control valve is characterized by being dividedat the divergence point 58 and supplied to the second control input line27. The second control input line 27 is another control input forconnection to the regeneration sequence valve. Accordingly, when thesecond electronic control valve is controlled to be switched to thesecond position, the compressed air in the regeneration line is suppliedto the second control input line through the second electronic controlvalve. Accordingly, a preferred embodiment of the present disclosure ischaracterized in that compressed air is supplied through two controlinput lines connected to the regeneration sequence valve, that is, thefirst control input line 26 and the second control input line 27.

In relation to this, the detailed structure of the regeneration sequencevalve 16 is described. The regeneration sequence valve 16 includes aspring to close the internal channel in a normal state, and isconfigured to be able to open when the spring is pressed by the pressureof air flowing inside from the input side. The air that is supplied tothe regeneration sequence valve 16 through the first control input line26 and the second control input line 27 presses the spring, and pushesthe spring such that the internal channel of the valve can be openedwhen it overcomes the spring force of the spring. For example,considering the pressure condition through the first control input line26 and the condition of the second control input line 27, it ispreferable that the regeneration sequence valve is set not to open whenpressure is applied from only any one of the two input lines and to openonly when pressure is applied from both of the two input lines. In thiscase, two electronic control valves may be simultaneously opened. Morepreferably, the lines may be controlled in two-stage control type suchthat pressure is applied through the first control input line 26 andcompressed air primarily flows inside (that is, the first electroniccontrol valve 31 is opened first) and then pressure is applied throughthe second control input line 27 (that is, the second electronic controlvalve 31 is opened later). In this case, the pressure of theregeneration sequence valve is increased step by step, so there is aneffect that the durability of the valve can be improved.

Accordingly, when the set pressure of the regeneration sequence valve isreached and the internal channel of the valve is opened, compressed airthat has passed through the first electronic control valve 31 and thesecond electronic control valve 35 can flows to the internal channel ofthe regeneration sequence valve through the first and second controlinput lines 26 and 27 and can be supplied to the regeneration line 45.

The opening conditions of the regeneration sequence valve are asfollows. First, when the electronic control unit 21 controls the firstelectronic control valve 31 to switch and the compressed air in the mainsupply line 42 flows into the control line 48, some of the compressedair flowing in the control lien 48 is supplied to the regenerationsequence valve 16 through the first control input line 26. Meanwhile,the set pressure of the regeneration sequence valve 16 is set higherthan the pressure of the air flowing inside through the control line 48,so the spring can be pressed and the internal channel of the valve canbe opened only when the pressure that is applied to the regenerationsequence valve gradually increases and exceeds the set pressure. Forexample, when compressed air flows into the control input side of theregeneration sequence valve 16, the regeneration sequence valve 16 isnot opened unless another control is performed.

In this case, when the second electronic control valve 35 is controlledto switch and the second control input line 27 is opened, pressureexceeding the set pressure of the regeneration sequence valve 16 isgenerated, so the regeneration sequence valve 16 is opened.

In relation to this, the regeneration sequence valve may have astructure in which predetermined pressure is maintained in accordancewith the initial pressure level of compressed air and then the pressurein the valve is gradually increased up to the set pressure of the valve,whereby the channel in the valve can be opened. To this end, the setpressure of the regeneration sequence valve 16 is set higher than thepressure of the compressed air in the main supply channel, andpreferably, the regeneration sequence valve 16 may be set to be openwhen a predetermined time passes after the first electronic controlvalve 31 is opened.

Accordingly, the regeneration sequence valve 16 is configured to be ableto open the regeneration line 45 by control input of an electroniccontrol valve, and preferably, may be a normally closed valve that isinstalled at the upstream side of the regeneration line 45.

Further, the regeneration sequence valve 16 is connected to theregeneration line 45 in which a regeneration check valve 17 isinstalled, and it flows back to the filter cartridge 14 through theregeneration line 45. The regeneration check valve 17, which is acomponent for preventing air in the regeneration line 45 from flowingbackward, enables the compressed air that has passed through the filtercartridge 14 to be supplied only to the main check valve 15 withoutflowing backward through the regeneration line 45 in the supplying step.In the regeneration process, the air flowing back to the filtercartridge 14 flows to the compressed air supply line 41 and isdischarged to the atmosphere through the exhaust outlet 52 after passingthrough the unloader valve 13. Further, a throttle 18 may be disposed onthe regeneration line 45. The throttle 18 is a pipe decreasing thediameter of a portion of the regeneration line 45. Compressed airflowing into the filter cartridge 14 decreases in pressure while passingthrough the throttle 18.

The regeneration line 45 may include a divergence point 55 and may beconnected to a sep-cooler through a sep-cooler exhaust line 46 and asep-cooler inlet port 54 that are connected to the divergence point 55.The sep-cooler is provided to filter out foreign substances such as oilcontained in the air flowing into the compressor. Accordingly,compressed air is supplied through the sep-cooler exhaust line 46diverging between the regeneration check valve 17 and the regenerationsequence valve 16, and is then discharged through an exhaust port of thesep-cooler after passing through the inside of the sep-cooler.Accordingly, in the regeneration step, it is possible to discharge theforeign substances remaining in the sep-cooler while regenerating thefilter cartridge 14.

Further, it is preferable that the second electronic control valve 35 iscontrolled by the electronic control unit such that the unloader valve13 is opened in advance before the regeneration sequence valve 16 opensthe regeneration line 45. Accordingly, regeneration is performed withthe compressed air in the compressed air supply line 41 sufficientlydischarged, so the regeneration efficiency can be improved.

For example, the electronic control valve 21 can simultaneously controlthe first electronic control valve 31 and the second electronic controlvalve 35 to switch, whereby opening the unloader valve 13 and convertingthe compressor into the unloading state can be finished before theregeneration sequence valve 16 is opened.

Hereafter, the operation of the compressed air processing systemaccording to the present disclosure is described with reference to FIG.1 according to the first embodiment of the present disclosure.

First, FIG. 1 shows the situation in which compressed air is suppliedwith the first electronic control valve 31 and the second electroniccontrol valve 35 at first positions, respectively.

Since both of the electronic control valves 31 and 35 are not operatedyet, so the regeneration line is in an inactivated state in FIG. 1. Indetail, when power is not supplied to the first electronic control valve31, the first port 32 of the first electronic control valve 31 isconnected with the vent 53 through the third port 34 and the pressurebetween the first port 32 and the regeneration sequence valve 16 doesnot reach the set pressure of the regeneration sequence valve 16, so theregeneration sequence valve 16 is closed, that is, the regeneration line5 keeps closed by the regeneration sequence valve 16.

Meanwhile, when cartridge regeneration is required, the first and secondelectronic control valves 31 and 35 are simultaneously or sequentiallyopened, so the regeneration sequence valve 16 is opened and thecompressed air in the main channel is supplied to the filter cartridgethrough the regeneration line, whereby regeneration is performed.

In an embodiment, the regeneration sequence valve 16 is configured suchthat when the air that has passed through the first electronic controlvalve 31 flows into the first control input line 26 of the regenerationsequence valve 16, the inflow air transmits pressure in a direction inwhich the spring 25 in the regeneration sequence valve 16 is compressed.Further, as the second electronic control valve 35 is controlled toswitch to the second position, air flows inside through the secondcontrol input line 27 of the regeneration sequence valve 16, andsimilarly, transmits pressure in the direction in which the spring inthe regeneration sequence valve 16 is compressed. If a preset operationpressure, that is, a set pressure of the regeneration sequence valve 16is reached, a channel in the valve connected to the regeneration line 45is formed while overcoming the restoring force of the spring.Accordingly, a delay is generated by the regeneration sequence valve 16by the time until the set pressure is reached, so regeneration isperformed with the unloader valve 13 opened first by the secondelectronic control valve 35.

A case in which two electronic control valves 31 and 35 are sequentiallycontrolled is exemplified. First, when the first electronic controlvalve 31 is controlled to switch to the second position, control inputis transmitted to the compressor control outlet 51 and simultaneouslycompressed air is also supplied to the first control input line 26 ofthe regeneration sequence valve 16. However, the pressure of theregeneration sequence valve 16 does not reach the set pressure, so theregeneration line 45 is not opened.

Thereafter, when the second electronic control valve 25 is opened andadditional pressure is supplied through the second control input line27, the pressure applied to the control pressure line 26 of theregeneration sequence valve 16 increases, so the set pressure isreached. Accordingly, the regeneration sequence valve 16 is opened andcompressed air is supplied to the filter cartridge 14, whereby theregeneration step is performed. In this case, as the second electroniccontrol valve is switched to the second position, the unloader valve 13is opened.

Therefore, according to a preferred embodiment of the presentdisclosure, as the second electronic control valve 35 is controlled toswitch by the electronic control unit 21, it is operated to open theunloader valve 13 first and then open the regeneration line 45 inaccordance with a delay.

Meanwhile, the electronic control unit 21 may be configured to performreturn control for maintaining the pressure in the system whenregeneration is finished. The return control may be performed in a wayof delaying the point in time at which the first electronic controlvalve returns to the first position. Preferably, when regeneration isfinished, the second electronic control valve is returned to the firstposition by turning off the second electronic control valve 35, but thefirst electronic control valve 21 is maintained in the on-state, thatis, maintained at the second position. In this case, the unloader valve13 is closed again as the second electronic control valve 35 is closed,so discharge of compressed air through the compressed air supply line 41is suppressed, whereby the internal pressure of the system can bequickly increased.

Meanwhile, a second embodiment of the present disclosure is shown inFIG. 2.

The example of FIG. 2 is substantially the same as the compressed airprocessing system of the first embodiment except for the structure ofthe regeneration sequence valve 16, particularly, the structure of thecontrol input line. That is, in FIG. 2, unlike FIG. 1, the second inputline 27 that supplies air through the second electronic control valve 35is connected to the first control input line 26 without being separatedfrom the first control input line 26. Accordingly, a check valve 28 forpreventing backflow of air is installed in the second control input line27. In the compressed air processing system of the second embodiment,the regeneration sequence valve 16 is opened only when the set pressureis reached by the compressed air flowing inside through the firstcontrol input line 26 and the second control input line 27, which is thesame as the first embodiment. In the embodiment of FIG. 2, there is aneffect that it is possible to simplify the structures of the channel inthe regeneration sequence valve and the plunger therein.

INDUSTRIAL APPLICABILITY

The present disclosure was described above on the basis of embodimentsand the accompanying drawings. However, the range of the presentdisclosure is not limited by the embodiments and drawings and may belimited only by claims to be described below.

1. A compressed air processing system for a commercial vehicle,comprising: a first electronic control valve controlled by an electroniccontrol unit; a second electronic control valve controlled by theelectronic control unit; and a regeneration sequence valve connectedwith the first electronic control valve and the second electroniccontrol valve and configured to open a regeneration line by receivingcontrol input through the first electronic control valve and the secondelectronic control valve, wherein the regeneration sequence valve isconfigured to open the regeneration line late by a delay until reachinga preset pressure by receiving air from the first electronic controlvalve and the second electronic control valve.
 2. The compressed airprocessing system of claim 1, further comprising: a compressor controloutlet connected to the first electronic control valve; and an unloadervalve connected to a compressed air supply line connected to acompressor, and pneumatically driven by receiving control input throughthe second electronic control valve, wherein the first electroniccontrol valve and the second electronic control valve are connected to amain supply line connected to the compressed air supply line.
 3. Thecompressed air processing system of claim 2, wherein the firstelectronic control valve is controlled to switch a valve position by theelectronic control unit and transmits air in the main supply line to thecompressor control outlet and the regeneration sequence valve, and thesecond electronic control valve is controlled to switch a valve positionby the electronic control unit and transmits the air in the main supplyline as control input for the unloader valve and the regenerationsequence valve, respectively.
 4. The compressed air processing system ofclaim 2, wherein the electronic control unit is configured to change thecompressor in a driving state by controlling the first electroniccontrol valve to switch and configured to open the unloader valve bycontrolling the second electronic control valve to switch; and theregeneration sequence valve operates to open the regeneration line onlywhen the first electronic control valve and the second electroniccontrol valve are both open.
 5. The compressed air processing system ofclaim 1, wherein the regeneration sequence valve is opened when thepressure of air that is input from the first electronic control valveand the second electronic control valve a preset pressure.
 6. Thecompressed air processing system of claim 2, wherein, in regeneration,the second electronic control valve is controlled to open the unloadervalve by the electronic control unit and the unloader valve is opened inadvance before the regeneration line is opened.
 7. The compressed airprocessing system of claim 1, wherein, in a regeneration mode, theelectronic control unit simultaneously or sequentially controls thefirst electronic control valve and the second electronic control valveto switch a valve position.
 8. The compressed air processing system ofclaim 2, wherein the unloader valve is configured to be opened byreceiving another control input from the compressed air supply line, andis configured to discharge air in the compressed air supply line to theoutside when the pressure of the compressed air supply line exceedspreset pressure.
 9. The compressed air processing system of claim 2,wherein a filter cartridge is installed between the compressed airsupply line and the main supply line, and a main check valve isinstalled between the filter cartridge line and the main supply line.10. The compressed air processing system of claim 9, wherein aregeneration check valve and a throttle are installed in theregeneration line.
 11. The compressed air processing system of claim 10,wherein a sep-cooler exhaust line diverging to a sep-cooler is connectedbetween the regeneration check valve and the regeneration sequencevalve.
 12. The compressed air processing system of claim 1, wherein theregeneration sequence valve is connected to a first control input lineinto which air flows through the first electronic control valve and asecond control input line into which air flows through the secondelectronic control valve and that is separated from the first controlinput line; and is configured to be opened by air supplied through thefirst control input line and the second control input line when internalpressure of the regeneration sequence valve reaches preset pressure. 13.The compressed air processing system of claim 1, wherein theregeneration sequence valve is connected to a first control input lineinto which air flows through the first electronic control valve and asecond control input line into which air flows through the secondelectronic control valve and that is connected to the first controlinput line; a check valve is installed between an intersection of thefirst control input line and the second control input line and thesecond electronic control valve; and the regeneration sequence valve isconfigured to be opened by air supplied through the first control inputline and the second control input line when internal pressure of theregeneration sequence valve reaches preset pressure.